1. Technical Field
The invention relates to a support structure for a vehicle such as a mount bracket that supports, for example, an engine.
2. Description of the Related Art
Examples of a support structure for a vehicle include an engine mount bracket. The engine mount bracket is disposed between a body and an engine to support the engine on a vehicle body. In association with a demand for a reduction in vehicle weight, castings (by the gravity die casting (GDC) process, the die casting (DC) process, or the like) made of a non-ferrous light alloy such as aluminum, copper, magnesium or an alloy thereof have been used for the support structures that support a vehicle part such as an engine. On the other hand, most of vehicle bodies, vehicle parts such as an engine and fastening members (bolts and the like) for fastening the vehicle part to a support structure for a vehicle are made of iron. When these dissimilar metals are combined together, a local corrosion cell may be formed on a surface of the support structure, which leads to as a so-called electrochemical corrosion reaction in which an aluminum alloy is dissolved.
In order to prevent the electrochemical corrosion reaction, for example, JP 2005-343418 A describes applying an corrosion proof treatment to an aluminum adapter (an example of a support structure for a vehicle) used to mount an engine on an iron rear frame (a vehicle body) by forming an insulating coating on the aluminum adapter.
Also, JP UM H03-026337 Y describes applying an anti-rust coating to outer surfaces of an aluminum holding member and an iron mounting bracket that is brought into contact with the holding member so as to cover the outer surfaces with the anti-rust coating.